Control system



C. B. BARTLEY ET AL June 1'7, 1930.

CONTROL SYSTEM Filed March -19, 1928 l u. l.

Patented June 17, 1930 CHARLES' B. BARTLEY VIRGIL H. DAKE, OF PITTSBURGH, PENNSYLVANA` CONTROL SYSTEM Application led March 19, 1928. Serial No. 262,698.

Ourinvention relates toelectro-magnetic devices and more particularlyto the type usually termed relays.l o

Certain vdisadvantages kare present in relays commonly employed in electric circuits generally. One disadvantage of the prior relays is the limited applicability of range of operationof a given type vof relay. Another is the inherent inability to function properly, or general .inetlectiveness and liability to damage when employed inv circuits subject y to widely varying current values, and the lack of sensitiveness and inability to respond to small current variations when used in connection Vwith circuits carrying relatively heavy currents.-y Further disadvantages of prior relays are that thev movement of relay parts maylag behind current changes to which the relay is intendedk to respond, and

also they may become ineffective without any Warning. These and other conditions necessitate choice, from among numerous types and designs of relays, of'a particular relay for a specific duty. v

The object of our invention generally stated is to provide an electro-magnetic device wherewith themovement of an armature isv eiij'ected in response to predetermined changes in a plurality of magnetic iields.

It is also an object of our invention to provide in anv electro-magnetic device for controlling the :liuxdensity of a magnetic iield in sucha way that the movement of an armature Vdisposed inthe field caused by change in `35 the magnitude of the field may be accurately and positively'predetermined.

A special object ofthe invention is to provide permeable means common to different magnetic lields for varying the effect of the magnetic-fields upon an armature actuated by changes in said fields. Y

yA further object of the invention is to provide a practical and dependable relay which may be adjusted to respond with as Agreat sensitiveness and rapidity when employed in a circuit in which small current values are encountered, as it will when employed in cir* n cuits carrying currents of relatively large values, and which will not be easily destroyed or rendered inoperative when relatively eX- cessive currents are encountered. r A still further object of the invention is to provide a relay whose marginal adjustments permit a variation of the limits of the relay operation both in respect to the width ot the margin and to the position of the margin with respect to the minimum and maximum current values for a particular capacity and design of relay. f

vOther objects of the invention are to provide a relay which is of simple, inexpensive and rugged construction, dependablein its operation, capable of rapid action, and whose adjustments are not readily disturbed, and 65 which is as useful for registering changes in or controlling alternating current as it is for direct current. o Y

rlhe invention may be embodied in a. relay comprising twospaced concentric solenoids which are adapted to carry currents of diiierent values, a core disposed in the-inner solenoid, and armature mounted longitudinally between the solenoids, and means for varying the density of the magnetic iiuX surrounding the solenoids for varying its eect upon the armature.

The invention is illustrated in the accompanying drawings, in which Figs. l and 2 are schematic, front and side elevational views respectively ot a relay embodying our invention; Fig. 3 an end view looking upwardly at the lower ends'or" Figs. l and 2 with the pole pieces removed; Figs. Ll, 5, and 6 schematic diagrams showing various circuit connections :tor the solenoid windings, and Fig. 7 a dia-grammatic representation of a particular application of the relay. In the drawings, all framework,l ,connecting members, and other partsnot essential or forming a part 9 of the invention have been omitted for simplicity of representation.

In accordance with the invention as em* bodied in the relay shown in the drawings, the outer solenoid l, Figs. 1 to 3, comprises a 95 coil ofv comparatively large low resistance current conduct-ing wire capable of carrying with safety a current greatly in excess of that normally passing through the relay. ,Mounts ,o ed concentric with, and disposed within the mi solenoid 1 is an inner solenoid 2 comprising a number of turns of smaller and higher resistance current conducting wire, but which has a factor of safet for carrying an excessive current that is substantially the same as that of solenoid 1. Y

In order that the number of turns of the outer solenoid 41 included in .aifpag ulg; cil"- cuit may be varied, taps 3 aire` pro ded" and connected to diierent points in thesolenoid ldiin @dem increase the Strength eifth magnetic 'field set up by the inner solenoid 2, an iron core member 4 is inserted in,the center of the solenoid. Disposed longitudinally between the two solenoilsla'rd pivots/ily supported at one endby apin 6 passing through it'and the core 4'is an armature 5, which is adapted to be actuated by the'ni'agrtic sux set up b the two solenoids. A spring I is provide to bias the free end .ofthe armature 5 laway fromA the longitudinallcenterof the inner solenoid to increase the length ofthe magnetic circuit.

vThe outer' solenoid 1 normally` has but small magnetic ell'ect upon the armature 5 because of the distance betweenthe two solenoids resulting inbut a ysmall 4portion ofits magnetic flux assingthrughthe armature andto deiinit y superimpose portions of the ma etic liux surrounding the solenoid 1, or forconcentrating of 'it upon lthe amature 5 to `control the operation of the armature, the manner more specifically described hereinafter, the oatin pole pieces `8 are rovided vand mount 'near the free endo the armature in a manner`(not shown) to allow forliorizontal'and vertical adjustment with `reference to ea'ch other, to the'sole'noids 1 and 2and to the armature 5'.' Infthis particular application, only two pole` pieces are shown, but it"will be vquite evident v'to thoseI skilled in the art that the number may be greatl varied. The pole pieces comprise materlal having high magnetic permeability characteristics, which may be employed in either its norma ly unmagnetized state or in ja' fpermanently Vmagnetized state, as the design of instrument ma require.

"In order that an e ectric circuit may `be made or interrupted when the armature 5is moved from one position Vto another, a movable contact member r9 is mounted on the armature 5, and adapted to make engagement with Ya fixed contact Ymember 11. lEvidently,

different tytpes of contact devices maybe di erent arrangements madewhere esire.

It is possible to mekeoperable vcircuit connections for the solenbids in a number ofyvarions ways without n' arting from the invention.' One/cnam eis illustated i'where th'tuter ai enoid' 1' 4sfcin d m series-circuit' relation with the cimit't be ont'roned; and' the* inner "solenoid 2' is short circuited upnitselrff 'In a lcircuit connection 1,765,045 l i n, K j

'is-shown connected in series circuit relation with-thee' cuitL-tp contr -ed,andt er soleiii'dZxis donnee edto gizionstantsueilgof supplyggsuch as a battery 12, thus maintaining a normally substantially constant ma natie pulln the amature 5 which may readily varied merel by changing ,the applied voltage. In Fig. 6 the solenoids, as illustrated, are connected in'parallel yrelation to each otherinthe circuit to be controlled. Accordingly, the relative changes in magneticiield valuesof the two solenolds will be substantially constant.` For most general purposes this latter connection has been found to be the preferred circuitM connec?. tion.

When the device or rela is inserted in an electric circuit and the 'po e ieces 8 are disposed in their most' inoperative osition, the

ines of flux set u paratively large diameter of that solenoid, spacing it at `a substaiitial distance from the core 4 of the inner solenoid 2 and the armature 5. The magnetic iluxsurrounding the inner solenoid@ when energizeglfhowevelr will be practically allconcentrsted in the core by the r solenoid will mostly all be 1n a1`r,because of the' 'coni-1 member 4 and the armature 5, asin the ordii naryzrelnI and asis weil known the' lines of ree seek their path of lowest `re sistance,l which in this instance is through the armature 5." ccordingly, the arxnaturel` is urged to a position to reduce the air gap be tween the armatures and the'co're 4 to a mink mum. Hence by adjust' the-tension in the spring 7, attached tothe amature 5, to different values, the magnetic 'pull' nece'ssaryi'to move the amature 5 can be predetermined, and asis also well known, the magneticipuil of a solenoid is proportional to the flowing in the solenoids, it follows that the spring can be adjusted to predetermine'th'e change in current to eect movement ofthe armature 5.

InY this invention, as yreferred to hereinbe. fore,the magnetic le pieces 8 are provided for the purpose o superimposing part o t the magnetic flux surrounding the outer sole,- noid upon the armature 5to ander oppose the movementA of the armature, and it will 'be readily understood by thosesli'illed in art thatb'y `erxlployilt auch means t0 sans@ the ma ,ntic nu; surrounding-the louter solev. noid 'w ich normally does not materially iniluence the armature 5 to either` aid or re the ffgort seeded Pe uitermate?? 5 by e KVao inner solenoid 2, that much finer and more sensitive adjustment of the armature movement can be-obtained. To more clearly understand the action of the relay, assume that .the spring 7 hasbeen adjusted to prevent movement ofthe armature 5 until a current of 10 amperes flows vin the circuit to be controlled, and also assume that normally the magnetici'ield of the -outer solenoid 1 does not materially affect the armature 5. It will be readily understood that by applying the flux produced `by the outer solenoid 1 to the armature and magnetic field of the inner solenoid, an attractingor repelling force can be brought to bear thereon, which may cause movement of the armature lwhen a current much less than 10 amperes is flowing in the main circuit, or Velse will not allow movement of the armature until a current of much more than 10 amperes flows-inthe main circuit, and the magnetic flux of the kouter solenoid can be so controlled to affect the movement of the armature by the useI of permeable magnetic pole pieces 8. The theory supporting this action is too well known to need explanation here.

To further amplifythe above, byprovidving for moving the pole pieces 8 substantially freely in thefields as suggested, an infiniteA 'number of different practically positive adjustments of the relay can `be accomplished. vEach ofthe pole pieces 8 therefor is made independently adjustable so as to vary the magnetic'iiuxintluenced by it, and depending upon its situation in the field in relation tothe outer solenoid 1 and the armature 5, each is capable of influencing the operation -of the armature 5. This use of the 'pole pieces for directing the influence of the magnetic flux of the outer solenoid 1,

. as 'stated above, secures greater sensitivity of the relay since the added eect of the flux set up by theouter solenoid 1 can be varied at willfby large or very .small increments, depending uponthe manner in which the pole pieces 8are disposed inthe magnetic yield.- When they are perpendicular to the core member 4- in theirmaXimum inner position, they will influence a minimum number of luX'flines from solenoidA 1, and as they are moved outwardly and perpendicularly, the magnitude of the flux inuenced by them willy be greatly increased, and their effectupon the armature 5-is augmented.

V"ln addition to the above, lby employing in `the inner solenoid 2 a conductor of very high resistance together with an iron core el therefor, a very small and light varmature 5 may be provided and adapted for movement inresponse to-but very small changes in current value in the inner solenoid, but which vchanges may correspond however to very large changes in the current in the vouter solenoid 2 depending upon the relative resistance values of the twosolenoids. In ac cordance with the description directed to the function of the movable pole pieces, it follows that though the relay is adapted for use with very large currents, and as the inner solenoid 2 and armature 5 are practically isolated from harm caused by current change, they can be made to function properly for very small changes in current in the circuit to be controlled, kor only for very large'changes, depending upon the adjustment of the pole pieces.

The fact that the armature biasing means and the number of turns in the'outer solenoid can be readily changed, also greatly mult-iplies the regulation and application of the relay.

By employing a type of construction described hereinbefore, a relay may be provided which is adapted to operate effectively and safely in circuits where currents of but a very few milliamperes are encountered, or in one where currents of thevorder of one hundred amperes are encountered, and its sensitivity can be readily controlled and varied in each application by adjustment of the pole pieces 8. F or example, it has been found that if but a very few milliamperes are flowing through solenoid 2, the relay can be set or adjusted to respond to an increase of one milliampere in the circuit, or it can be adjusted to operate at Vanyother value, such as one ampere, or more, as the necessity or requirements may be to givel a wider margin of inoperative current flux. It has alsobeen found that it can be regulated to be inoperative over currents of'greatly wider margin than this, even tothe extent of exercising its control only upon the advent of excessively large current surges. ,n Y

lt will be evident to those skilled in the art that the solenoids may be constructed from conductors of varying current carrying capacities and with or without a core member to provide magnetic ields of any desired strength or any desired ratio as the application of the' relay may necessitate.

Relays constructed in accordance with the invention may be adapted for a large variety of uses such as for use in the operation or' control devices like alarms, signal lights, and

numerous other purposes. A particular application of a relay of this character is illustrated in Fig. 7 in connection with a power transmission system where it isutilized for recording unbalanced conditions, such as are encountered by Hash-overs of short duration or momentary breakdowns due to lightning or other causes in the distribution of current. In Fig. 7, the three-phase transmission line is illustrated comprising three conductors 13, 14 and 15 connected to a neutral lead 16 which in turn is connected through the primary winding 17 of the transformer 18 to the ground. The secondary winding 19 of the transformer 18 is connected toa relay constructed in accordance with the invention, lindicated generally at 20,.wi th.the outer Solenoid 1 and the `inner solenoid 2 con-- the movable Contact member 9 vagainst, the

iixed Contact member 11to close an electric circuit through conductors 21 and 22 which may lead to a control device suchy as a circuit breaker located at any desired point. In this ,y particular case, the relay may be adjusted so that when normal conditions prevail in the transmission line, the .armature will not close the contacts to complete the circuit ofwhich conductors 21 and 22 are a part However, upon occurrence of a disturbance, such as an unbalanced condition, vor a flash-over between any of lthe conductors ofthe transmission line, the current surgecreated ,thereby `in passing through the-relay will cause sulicient increase in flux density inthe relay as controlled by the floating pole pieces 8 as to cause the armature to be'immediately moved to a position to'closethe contactmcmbers 9 and' 11, and oompletethe circuit 4.which they control.

In view -of the fact that the outer .solenoid which in conjuni'on' with the floating pole piecesact as a sort of kvalve for controlling the operation of the armature having smagneticiield substantially all in air, various uctuations in the magnitude of the magnetic eld created by thiscoil may occur with great rapidity. Consequently, the relay. will be exceptionally quick to operate vand it has been iolmd, for example, that its contacts will close during a fraction of the .initial alternaf tion of a half-cycle ofl a sixty-cycle power system. A g t It has also .been found thatzby disping the movable pole pieces 8 in various positions in the magnetic field of the solenoid 1, their inuence upon the armature 5 .can be so adjustedas to `retard the rapid actionof the .armature due to the change in eiect thereon as lit moves from one position to another. ,y The wide range of applicability of the re- 6D lay, both with very small and verylheavy v currents, together with its selectivity to be operated under wide or narrow ranges. of both large and small Ycurrents is of great importance. The combination with a solenoid adapted to carry heavy-currents continuously, of a solenoid of relatively high resistance capable of carryin va wide range of, iow Minets continnou y, and am armature with means for deh'cately adiusting and varying the ma etio fields provided by the solenoids upon t e armature,Y rovides ra: relay which combines simple an durable construction Vwith great Yutility `and applicability. Y

According to the provisions of the patent statutes, we how explained the principle and mode of e ationrof our invention, and have illustratednd described what we consider to bel its best embodiments. yEIowever, we desire tohavefit understood that, within the scope oflthe appended-claims, the invention may be practiced otherwise than as specifically illustrated and'described.

We claim as our invention: 1. In an electro-magnet comprising a ,plurality of solenoids concentrically mounted one within the other, an amature disposed to beactuated by the magnetic uxsurroun said soldnoids,and permeable means ada to be adjusted to vary the amount of magnetic iux aifectin lthe armature.

2. In anmy ectro-magnet comprising a. pair of magnetic coils concentrieally mounted one within the other, a movably mounted armature ixierposed between `said coils and a permeableA member adapted to be adjusted to (g5 diierent positions in relation? to said armature and said coils to -vary .the effect upon the `armature of the magnetic flux surround-- ingsazidcoiis.

3. in an electric-relay, `the combination e! sa an inner and an outer concentric radially spaced solenoidacore'disposed coaxially within said inner solenoid, an uarmature mou for movement in response to energizationof said solenoids, and means for adustabiy varying thel effect of the magnetic ux sur` rounding the outer "solenoid upon' the armature. f

4. In an electric relay-theV combination of y an inner and an outer concentric radialiy spaced solenoid, a core disposed coaxialiy' within said inner solenoid and an armature mounted fior movement' infresponse to exil ergizationo said solenoids, means for bissl ing said armature to a predetermined posi`- T tion, and means for adjustably varying the effect of the magnetic linx-surrounding the outer solenoid upon the armature to predetermine the operation of said armature.

5. In an electric relay the combination of in Aan innery and an outer concentric radially spaced solenoid, an amature mounted for movement n-'lve'sponseto energiz'ation of said' solenoids, andva permeable member movably mounted-for varying the eiect upon the arm- H5 ature1 magnetic dx surrounding th outer 'soldnoid. 6. `In Inelectric relay the combination ofv an inner'f and an outer concentric 'radially spaced solenoid, an armature pivotally '12 mounted for movement in response to the magnetic field surrounding said eolenoidg whenencrgized, anda plurality of members movabiy mounted and adaiedtg vary the eiect upon the armature of-t "5125 netic field surround' the outer solenoidi 7. In aneectric ""thclcombination of y, an inner vsolenoid mounted u a permeable core, an armature mounted r movement in response/fte the magnetic *Huf-surrounding w said solenoid when energized, an outer solenoid mounted coaxially with said inner solenoid and spaced therefrom so that the magnetic' flux surrounding said outer solenoid when energized normally will not aect the armature, and means for adjustably superimposing diierentamounts of the magnetic flux surrounding said outer solenoid upon the magnetic iield of said inner solenoid to eect the movement of the armature.

8. In an electro-magnet the combination of a plurality of solenoids disposed to have overlapping magnetic iields, a movable armature mounted in a way to be actuated by the magnetic flux surrounding said solenoids, and a movably mounted member having high magnetic permeability characteristics for changing the flux density of the magnetic elds affecting the armature.

9. ln an electric relay the combination of an outer and an inner solenoid, a permeable core member disposed in a fixed position within said inner solenoid, an armature mounted for movement in response to the energization of said solenoids, the outer solenoid being spaced so that normally its magnetic field does not materially affect the movement of the armature and a movable pole piece adapted to influence a portion of the magnetic ux surrounding the outer solenoid to affect said armature, and means for predetermining the magnetic effort ot said solenoids necessary to move said armature. y

l0. ln combination with an electrical circuit to be controlled, a movable circuit controlling element, means for actuating said movable circuit controlling element comprising a plurality of windings that carry current varying in the same sense as the current in theV circuit to be controlled, and means mechanically independent of said movable element but associated therewith and with said windings whereby the torque exerted on said movable element can be varied to different amounts without necessitating current changes in the circuit to be controlled.

" 11. In combination with an elect-rical circuitv to be controlled, a movable circuit controlling element, means for actuating said movable controlling element comprising a plurality of windings carrying different values of current but varying in the same sense as the current inthe circuit to be controlled, means mechanically independent of said movable element for varying the torque exerted on said'movable element without affecting the current in the windings, and means for predetermining the torque necessary to eii'ect movement of the movable element.

12. An electro-magnetic circuit controlling device comprising a movable circuit controlling element and means for causing movement of said element on theoccurrence in the circuit to be controlled of current changesv of a predetermined character, said means comprising a plurality of concentrically spaced wind` ings that carry current of different values varying in the same sense as the current in the circuit to be controlled, and mechanically independent permeable means for varying the torque exerted on the movablel member independently of the current in the windings, and resilient means for predetermining the torque necessary to eiiect movement of the movable element.

13. ln an electro-magnetic device comprising two concentrically spaced windings, an armature pivotally disposed longitudinally between the windings, and means for varying the magnetic torque exerted upon the armature.

14. An electro-magnetic device comprising in combination a solenoid, an armature mounted for movement transverse to the axis of the solenoid and in response to the current conditions therein, and adjustable permeable means for varying the eHect upon the armature of the magnetic flux surrounding the solenoid.

15. An electro-magnetic device comprising in combi-nation a solenoid of substantial diameter, a permeable core concentrically mounted longitudinally within said solenoid, an armature mounted for movement transverse to the axis of said core and solenoid and in response to the current conditions in the latter, and adjustable permeable members for varying the e'ect upon the armature of the magnetic iux surrounding the solenoid.

16. An electromagnetic device comprising a solenoid having a substantial diameter, an armature mounted inside of said solenoid and arranged for movement transverse to the longitudinal axis of and in response to the changes in magnetic iield there-within, and means for biasing said armature away from the longitudinal axis of the solenoid.

17. An electro-magnetic device comprising a'solenoid having a substantial diameter, a permeable core longitudinally disposed within said solenoid, an armature also mounted within said solenoid and arranged for movenient transverse to the longitudinal axis of said core and in response to variations in the magnetic ield in the solenoid, and means biasing said armature away from the longitudinal center of said core.

ln testimony whereof, we hereunto sign our names.

CHARLES B. BARTLEY. VIRGIL H. DAKE. 

